Earn while you tweet | URL Shortener Services that pay

Yes thats true, there are some URL shortener services that actually pay you for using their services. Though the earnings will not make you feel any richer, still every buck counts. So how does it work, it is pretty simple to use such a service. All you need to do is to go to their respective home page and register one account. Now whenever you create a short URL and use it and when someone clicks that URL, you get paid. As you must be knowing that URL shortener services are mostly used while one tweets . Twitter has a limitation of 140 character count for any tweet, this makes it necessary to shorten any URL you are planning to post in Twitter.
monetize your tweetsadf.ly pays you 4 $ for every 1000 clicks on shortened URL that you post. Payents are done through Paypal and Alertpay. So if you have tons of followers in Twitter, you can expect to make some good money with this service.
Few other such services are